% 










"/. 






V _<#"<%, 



7 <&***. 











*$* -y^ * AwA," \$> c$ 

/.•jxiX'-y ^ 



? .. y\ v^W- : /k -•: 








W 



** v \ 




W 









V^' 















A 







-0 »L^L'* ^> V 






V • — •<►♦ % ^-* / 












v-o^ 




v - • * « ♦ ^b A 



^ ^ 






,* v \ 



o > 








^/"- 4 > 



CO 

o V* 




v v 



<* .^ ^ --^aw/ ^' % °*y$w/ ^^. j .m»*° A ^^ iws?.- ^v ^ 



«<SS 



aV 



o. *< 

















^ ^^^^ A 



A u '<> *o»o' a* c q, ♦TV," A 



AT 






»bt? 



V 



»' > 



o_ * 









WW*' < s 

tt -Sill: "° v =i§l*: " 0< :% ".v* :£%£'•+■>* 

' • A ^. 

* <P ^ • 
,A <** 



fee 



V 1 V y 

V % J> * 










>- c^ jy -•••• ^ «* 














J°« 



1. ° ^c,' 



O' ,--3 






.U" o 



a, w ^s> * «o' y q, *• 






°o. 



^ c „_«<,,_ * .^ 



V 













iP^ 






V ^-o ^ q^, ••.*•• a° v. *°" ' ^ 













.5' 41 A <V 

q^ ^-' ^ V 

Vc V A^ * v ^fe'. ^ ^ 



V\ 



■^ 







I 



^°^ 












" 





" v™-'^ % J ^^'/^ v-»v' %/ 



a v ;-^> ^ ,0* .mv.*o 



vvi* v v <^ a° q, 



A^, 



•f. a"» 



A 



• 'V 



JC 9065 



Bureau of Mines Information Circular/1986 



Evaluation of Safety Shutoff Valve 
System on Methane Gas Pipelines 
Under Mine Fire Conditions 



By Patrick A. Kinek, Thomas E. Marshall, 
and Gerald L. Finfinger 




UNITED STATES DEPARTMENT OF THE INTERIOR 



•jcAjf^h, 



Information Circular 9065 

,1 A 



Evaluation of Safety Shutoff Valve 
System on Methane Gas Pipelines 
Under Mine Fire Conditions 



By Patrick A. Kinek, Thomas E. Marshall, 
and Gerald L. Finfinger 




UNITED STATES DEPARTMENT OF THE INTERIOR 
Donald Paul Hodel, Secretary 

BUREAU OF MINES 
Robert C. Horton, Director 








Library of Congress Cataloging in Publication Data: 



Kinek, Patrick A 

Evaluation of safety shutoff valve system on methane gas pipelines 
under mine fire conditions. 

(Information circular / United States Department of the Interior, 
Bureau of Mines ; 9065) 

Bibliography: p. 7. 

Supt. of Docs, no.: I 28.27: 9065. 

1. Coalbed methane drainage. 2. Relief valves. 3. Mine fires. 
4. Coalbed methane — Pipe lines. I. Marshall, Thomas E. II. Fin- 
finger, Gerald L. III. Title. IV. Series: Information circular (United 
States. Bureau of Mines) ; 9065. 

TN295.U4 [TN3051 622s [6 22'. 81 85-600311 



CONTENTS 

Page 

Abstract 1 

Introduction 2 

Acknowledgments 2 

Survey of valve manufacturers 2 

Investigation of insulation techniques 3 

Field tests of ball valves 3 

Field test of the "fire bag" 6 

Conclusions 6 

References 

ILLUSTRATIONS 

1. Test setup for temperature durability evaluations 4 

2. Components of brass valve 5 

3. Results of fire test 5 

4. Closeup of a brass valve protected with a "fire bag" 6 





UNIT OF MEASURE 


ABBREVIATIONS 


USED IN 


THIS REPORT 


°c 


degree Celsius 




lb/ft 3 


pound per cubic foot 


ft 2 


square foot 




min 


minute 


gal 


gallon 




psig 


pound per square inch, 
gauge 


h 


hour 




s 


second 


in 


inch 








lb 


pound (mass) 









EVALUATION OF SAFETY SHUTOFF VALVE SYSTEM ON METHANE GAS 
PIPELINES UNDER MINE FIRE CONDITIONS 

By Patrick A. Kinek, 1 Thomas E. Marshall, 2 and Gerald L. Finfinger 3 



ABSTRACT 

The purpose of this investigation was to evaluate the integrity of the 
existing shutoff valves and actuators used under high-temperature condi- 
tions in the Bureau of Mines' horizontal borehole methane drainage pipe- 
line system and to determine the potential for improvement in the 
system. 

In the field tests, both fire-safe ball valves and standard brass ball 
valves were initially subjected to a 30-min pan fire without thermal 
protection. Neither valve could maintain line pressure beyond 11 min in 
a fire that reached temperatures between 500° and 700° C. 

Based on the test results, it was concluded that the brass ball valve 
used in the Bureau's methane drainage pipeline system can be retrofitted 
with an inexpensive "fire bag" to substantially increase its integrity 
under mine fire conditions. 

1 Mining engineer. 
^Engineering technician. 
•^Supervisory geologist. 
Pittsburgh Research Center, Bureau of Mines, Pittsburgh, PA. 



tm 



INTRODUCTION 



Methane gas is an inherent safety haz- 
ard in underground coal mining. In re- 
sponse to this hazard, the Bureau of 
Mines instituted a methane drainage pro- 
gram that has undertaken numerous im- 
provements over the years ( 1-3 ). 4 A ma- 
jor objective of these improvements has 
been in the area of the pipeline safety 
system. This system consists of numerous 
fail-safe mechanisms that control drain- 
age of methane gas under normal and emer- 
gency conditions. One emergency condi- 
tion for which the system had not been 
tested was its behavior when subjected to 
a mine fire. Although the occurrence of 
a mine fire in the life of a mine is very 
infrequent, the effects of mine fires can 
be dramatically worsened by gas leaks 
from underground methane gas pipelines. 



The Bureau and the Mine Safety and 
Health Administration (MSHA) are con- 
cerned about this fire hazard because the 
implementation of methane drainage pro- 
grams in U.S. coal mines will increase as 
gassier mines are worked. Although only 
a handful of drainage programs currently 
exist, one mine with a methane drainage 
operation has already had a fire that re- 
sulted in extensive property damage (4_) . 

At the request of MSHA, the Bureau un- 
dertook the present investigation to de- 
termine the integrity of the existing 
shutoff valves and actuators used in its 
methane drainage pipeline system when 
subjected to high temperatures such as 
those encountered in a mine fire, and to 
study the potential for improvement in 
the system. 



ACKNOWLEDGMENTS 



The cooperation and efforts of members 
of the Fire and Explosions Group, Bureau 
of Mines, Pittsburgh Research Center, 
are greatly appreciated. In particular, 
Charles P. Lazzara, Supervisory Research 
Chemist, and Frank Perzak, Research 



Chemist, were instrumental in the initial 
investigation of valve manufacturing and 
insulation techniques. The authors would 
also like to thank Frank Perzak for his 
effort in setting up and monitoring the 
fire tests at Lake Lynn Laboratories. 



SURVEY OF VALVE MANUFACTURERS 



The investigation began with an inquiry 
to determine whether any ball valve manu- 
facturer or commercial testing company 
did any high-temperature performance de- 
sign and testing on ball valves used to 
regulate gas. It was found that all 
high-temperature ball valve designs as- 
sumed that a liquid was being regulated 
(usually a petroleum product), and that 
all performance criteria (leakage rates) 
during testing of valves were based upon 
the regulation of a test liquid (water). 
It appeared that previous to the Bureau 
inquiry, no one had ever asked for a ball 
valve that would regulate gas under fire 
conditions. The basis for the industry's 
current design of fire-safe valves is 
the ability of a liquid under pressure to 
create a "bubble seal" between the ball 



and the valve body after the Teflon 5 seat 
has burned away. Since a single gas 
phase does not have this property, exist- 
ing fire-safe valves are not applicable 
to the methane drainage system. 

One manufacturer suggested the use of 
either ball valves with seats, seals, and 
body parts made out of expensive ma- 
terials (i.e., graphite, stainless steel, 
etc.) or more expensive, custom-designed 
wafer valves. However, both of these 
solutions would have meant an 8- to 10- 
fold increase over the cost of the pre- 
sently used valves. Accordingly, it was 
decided to see if the present ball valve 
or a more expensive, fire-safe ball valve 
could be insulated from the high temper- 
atures resulting from a mine fire. 



Underlined numbers in parentheses re- 
fer to items in the list of references at 
the end of this report. 



^Reference to specific products does 
not implv endorsement by the Bureau of 
Mines. 



INVESTIGATION OF INSULATION TECHNIQUES 



The insulation technique had to be (1) 
relatively inexpensive, (2) easily retro- 
fitted, and (3) accessible when valve 
maintenance was required. Only two insu- 
lation techniques are currently being 
used in the valve and actuator industry. 
The first technique is the application of 
a thin coating of epoxy-based substance 
which during a fire swells up and chars 
(an intumescence) , forming an insulation 
barrier. However, its use was not recom- 
mended because of the temperatures and 
duration of the type of fire under con- 
sideration and because of expense. 

The alternative available insulation 
technique was a "fire bag" made from 
inexpensive ceramic fiber and fiber- 
glass (Kaowool, $1.70/ ft 2 ). 6 A 2-in- 
thick, 8-lb/f t 3 -density material was 
used. The fiberous material is wrapped 
in an inexpensive, fire-resistant jacket 
($0.80/ft 2 ), having a silicon rubber 



coating with a fiberglass base that pro- 
vides a weather-resistant barrier. The 
total cost of materials used to construct 
the "fire bag" (1 ft 2 of Kaowool, 2 ft 2 
of fire-resistant jacket material, and 
two hose clamps) was approximately $6. 
This more than satisfied the first speci- 
fication of low relative cost. 

The second requirement was that the in- 
sulation technique had to be easily re- 
trofitted. The "fire bag" was measured 
and cut in the field with a tape measure 
and a simple utility knife. Approxi- 
mately 10 to 15 min was required to con- 
struct it. Since all the valve-actuator 
components in a mine would be identical, 
the same pattern can be used for all the 
valves. 

The third requirement of valve accessi- 
bility was achieved as the fire-resistant 
jacket can be easily removed and replaced 
by loosening the two hose clamps. 



FIELD TESTS OF BALL VALVES 



Field tests were conducted at the 
Bureau's Lake Lynn Laboratory. A series 
of pan fire tests was performed on the 
ball valves , using kerosene as the bulk 
fuel and heptane as the starter fuel. 
The test set up consisted of two 
10-ft sections of 2-in-diam, standard, 
schedule 40 steel pipe connected to 
either end of the ball valve. The ends 
of the pipe were supported, so that the 
valve was suspended over the fire pan 
(fig. 1). One pipe section was sealed 
and pressurized with nitrogen gas. The 
nitrogen gas leakage rate was monitored 
with a pressure gauge and a flow meter. 
Three thermocouples were used to monitor 
the temperature of the fire, the outside 
valve body temperature, and the internal 
temperature of the valve body around the 
Teflon seat (fig. 2). The pressure 
gauge, flow meter, and elapsed time were 
continuously monitored with a video 
camera. Thermocouple temperatures were 
monitored using strip chart recorders and 
a microprocessor. 

^Prices for equipment are based on July 
1984 data. 



Two ball valves were initially tested 
without an actuator or any thermal pro- 
tection: a fire-safe valve and the 
brass valve currently used by the Bureau. 
The fire-safe ball valve was constructed 
of stainless steel with a Teflon seat and 
an asbestos stem seal. The Bureau valve 
has a brass body with a Teflon seat and a 
Teflon stem seal; its cost is about one- 
fourth that of the fire-safe valve. 

For each test the valves were turned to 
the closed position so that nitrogen gas 
could fill the pipeline. A line pressure 
of 20 psig was put on the valves to simu- 
late the low pressures observed in a 
shutoff methane drainage pipeline. Line 
pressure in a shutoff methane drainage 
pipeline can reach in situ gas pressures 
well in excess of 20 psig if allowed to 
build for 24 h or more. However, in a 
mine fire emergency, shutoff valves at 
the collars of the holes would be closed 
as soon as the fire was detected by the 
pipeline safety system or by mine person- 
nel. Thus, during the subsequent criti- 
cal minutes of the early life of the 
fire, line pressure would remain low. 




FIGURE I. - Test setup for temperature durability evaluations. 




FIGURE 2. - Components of brass valve. 



Initially, in each test, a pan fire 
using 15 gal of kerosene was ignited un- 
der the unprotected valve, producing tem- 
peratures of 500° to 700° C over a 30-min 
period. Both valves recorded an in- 
ternal temperature of 500° to 550° C on 
the seats at 11 min (fig. 3); this is the 
temperature range in which Teflon polymer 
begins decomposing extensively. Not sur- 
prisingly, for tests with both valves the 
flow meter began rising after approxi- 
mately 11 min, indicating a leak in the 
system through the valve. 

An important observation was that the 
inexpensive brass valve performed as well 
as the more expensive fire-safe valve. 
Low line pressure and the absence of a 
liquid medium rendered the fire-safe 
valve as ineffective at high temperatures 
as the brass valve. Given this finding, 
it was decided to use only the brass 
valve for the "fire bag" tests. 



800 




20 
TIME, min 

FIGURE 3. - Results of fire test. 




FIGURE 4. - Closeup of a brass valve protected with a "fire bag. 



FIELD TEST OF THE "FIRE BAG" 



A complete shutoff valve system was 
constructed for the "fire bag" tests. An 
air actuator was attached to the normally 
closed brass valve, and 60 psig of air 
was applied to the actuator through 1/2- 
in PVC pipe to keep the valve open (fig. 
4) . The initial reason that PVC pipe was 
chosen to carry air to the actuators was 
that it is inexpensive and would break 
easily if there were a roof fall on the 
pipeline ( 1_) . Line pressure would drop 
once the pipe was broken, causing all 
valves in the system to move to the 
closed position and thus halting methane 
gas flow. Given the fact that the PVC 
pipe being used had a low melting point, 
it could also serve as a fire warning 
mechanism. The same series of shutoff 
events would occur once the PVC pipe 
burned through as when the pipe was 
broken by a roof fall. 



Once the shutoff valve system was con- 
structed, the valve was wrapped in the 
"fire bag." Twenty gallons of kerosene 
was used for these tests to extend the 
life of the fire from 30 min to 40 min. 
The kerosene was ignited, and after 
20 s the PVC pipe burst, confirming its 
effectiveness as a fire warning mecha- 
nism. As a result, air pressure on the 
actuator was released, causing the valve 
to close and stopping the flow of nitro- 
gen gas. After 40 min of fire exposure 
at temperatures between 500° and 700° C, 
the ball valve seat and stem seal were 
still intact and maintaining line pres- 
sure. The internal temperature on the 
Teflon seat was only 380° C at the end of 
the 40-min period (fig. 3) , as compared 
with 550° C after 11 min without the 
"fire bag" (fig. 3) . 



CONCLUSIONS 



The results of the investigation indi- 
cate that the ball valves now used in the 
Bureau's methane drainage pipeline system 
can be retrofitted with an inexpensive 
"fire bag" to substantially increase the 
system's short-term integrity under mine 
fire conditions. It was also established 
that the more expensive fire-safe ball 
valves are no more effective at sealing 



a low-pressure gas line under high- 
temperature conditions than a thermally 
unprotected brass ball valve. 

It was also found that normal 1/2-in 
PVC pipe can function not only as a roof 
fall warning system, but also, because of 
its low melting point, as a fire warning 
system for methane gas pipeline. 



REFERENCES 



1. Tongue, D. W. , D. D. Schuster, R. 
Niedbala, and D. M. Bondurant. Design 
and Recommended Specifications for a Safe 
Methane Gas Piping System (contract 
J0155145, Energy Applications Inc.). Bu- 
Mines OFR 109-76, 1976, 97 pp.; NTIS PB 
259 340/ AS. 

2. Prosser, L. J., G. L. Finfinger, 
and J. Cervik. Methane Drainage Study 
Using an Underground Pipeline, Marianna 
Mine 58. BuMines RI 8577, 1981, 29 pp. 



3. Irani, M. C, F. F. Kapsch, P. W. 
Jeran, and S. J. Pepperney. A Fail-Safe 
Control System for a Mine Methane Pipe- 
line. BuMines RI 8424, 1980, 11 pp. 

4 . Mann , F . C . , J . V . Bowman , and 
W. W. Hulvey. Report of Investigation 
(Underground Coal Mine) . Mine Fire and 
Explosion, VP-5 Mine (ID No. 44-03795), 
VP-5 Mining Company, Vansant, Buchanan 
County, Virginia. Mine Safety and Health 
Administration, Apr. 15, 1982, 14 pp. 



■nnnmwinamM^mnfifi 



Mnttai 



U.S. Department of the Interior 
Bureau of Mines— Prod, and Distr. 
Cochrans Mill Road 
P.O. Box 18070 
Pittsburgh. Pa. 15236 



AN EQUAL OPPORTUNITY EMPLOYER 



OFFICIALBUSINESS 
PENALTY FOR PRIVATE US£ $300 

"2 Do not wi sh to receive thi s 
material, please remove 
from your mailing list* 

~2 Address change* Please 
correct as indicated* 



H 153 86 






K 



>«*, 



^°<* \^^' £*+ '"His" * **°* : *£uf>* ^-n*. 

*v\/ V^V V»\/ <9\# V>^'\^ 




**o« 




r <> -o.o' a> 






"<$> » O N O ' A 



■& vV^ * iCCV S» A ^V> C. 



o > 






v- v 









> 



1 *L!nL'* "> V 



°* *'-•' *°- "^ -«• ..To '* # °o *»rr; •** .o° 





O « 



rj» A ' iA sf /k ^r. C^ * 






*bv* :£nm5*\ ^«<" .v^war- v..v .*^^,'. 



^o* 



^0^ 






^oV 



* < 



o. *, 






"W 






A v 






A. <!> * . » .<?> V 

^ ^ *s 



'. *o 



^ .. 



^ ,c^.% ^_ 



v " ' * °- ^ 

>^ «/ *(\§>^^» ^ a"* * 









v^ 1 



>n 









■ SX ''W?J J\ . wr . 



o V . ;jV^ 



-^o^ 



'bv* 






^ * . , 1 • ' f 



^^ 



a7 * 













°* ^b 



^ .. 






', ^^ ,-^Va\ ^ .^ .y 



•^ 

Xp^ 





^5°* 






o > 
» ^ 




"oV 



»°v. 








^i* N --*m2^\ '+ Mf $' v^» V^ s*"/^-- T 






•\* 













* V 

0* ••JL"» o 4> .^" 

























• -I, \f- <^ 









"oV" 






v^ . 











